package com.alan.gulimall.product.service.impl;

import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.alan.common.utils.PageUtils;
import com.alan.common.utils.Query;

import com.alan.gulimall.product.dao.CategoryDao;
import com.alan.gulimall.product.entity.CategoryEntity;
import com.alan.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        //1.查出所有分类
        List<CategoryEntity> entities=baseMapper.selectList(null);
        //2.组装成父子的树形结构
        //2.1 找到所有的一级分类


//          通过stream Api判断实体的父Id是不是0获取一级分类 过滤返回
//          类似于:
//          List<CategoryEntity> list1=new ArrayList<>();
//           for (CategoryEntity entity:entities) {
//           if(entity.getParentCid()==0){
//                list1.add(entity);
//           }
//         }
//         不过stream是线程调用 简单处理时for循环较快
//         map表示对数据进行更改

        List<CategoryEntity> level1Menus = entities.stream().filter(categoryEntity ->
             categoryEntity.getParentCid() == 0
        ).map((menu)->{
            menu.setChildrenCategoryEntity(getChildrens(menu,entities));
            return menu;
        }).sorted((menu1,menu2)->{
            return (menu1.getSort()==null?0:menu1.getSort())-(menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());
        return level1Menus;
    }

    @Override
    public void removeMenuByIds(List<Long> asList) {
        //TODO 检查当前删除的菜单，是否被别的地方引用
        //开发时使用逻辑删除
        //调用mybatisplus的批量删除方法进行删除
        //物理删除
        baseMapper.deleteBatchIds(asList);
    }

    /**
     * 递归查找所有菜单的子菜单
     * @param root
     * @param all
     * @return
     */
    private List<CategoryEntity> getChildrens(CategoryEntity root,List<CategoryEntity> all){
        List<CategoryEntity> children=all.stream().filter(categoryEntity -> {
            return categoryEntity.getParentCid().equals(root.getCatId());
        }).map(categoryEntity -> {
            categoryEntity.setChildrenCategoryEntity(getChildrens(categoryEntity,all));
            return categoryEntity;
        }).sorted((menu1,menu2)->{
            return (menu1.getSort()==null?0:menu1.getSort())-(menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());
        return children;
    }
}